James Holmes' has had a variety of haircuts and facial hair during his court appearances and in photos from before his arrest.

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ARAPAHOE COUNTY, Colo. - Lawyers for the man charged in the Aurora movie theater massacre have asked the state Supreme Court to overturn the presiding judge's order for a second sanity evaluation, but the appeal is being kept secret for now.

In documents released Tuesday, defense lawyers confirmed they filed the appeal and asked that the document remain out of the public's view.

James Holmes pleaded not guilty by reason of insanity to charges of killing 12 people and injuring 70 in the 2012 attack.

He underwent a mandatory sanity evaluation last summer, but according to court documents, the judge concluded that the first evaluation of Holmes conducted by the Colorado Mental Health Institute at Pueblo was incomplete and inadequate.

No other details from the first exam have not been made public.

The judge granted prosecutors' request for a second evaluation but said it should be done by another doctor at the state hospital, not by doctors chosen by the prosecutors.

If jurors eventually decide Holmes was insane, he would be acquitted of the crimes and committed indefinitely to the state hospital. If they decide he was sane, he could be convicted and sentenced either to be executed or spend life in prison without parole.

Holmes' attorneys acknowledged that he was the shooter. The case now hinges on whether he was insane.

Veteran defense attorney Dan Recht says the judge’s order calling for another exam is extremely rare.

"It's highly unusual a judge would issue a new sanity evaluation,” said Recht. "I've not seen it happen in my practice."

Copyright 2014 Scripps Media, Inc. The Associated Press contributed to this report. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.